Hip fixation device

ABSTRACT

A hip fixation device for reconstructing fractures of the upper end of the femur comprising a spoon-shaped plate having a handle portion which extends laterally along the top of the femur shaft and a bowl portion which conforms to the lower portion of the greater trochanter. A plurality of bores transverse the bowl portion for receiving hip screws adapted to be driven into the upper end of the femur generally parallel to the long axis of the femur head and a flat headed boss surrounds the outer opening of each bore against which the undersides of the screw heads seat. A cover plate is attached tightly over the outer side of the bowl portion against the screw heads by means of bolts. It has a raised section on its inner side which fits down between the screw heads to keep them from rotating. A pair of bending tools for bending the spoon shaped plate so that it conforms to the femur contour and a driving tool for driving the hip screws into the femur are also disclosed.

llnited States Patent 1191 Wagner [451 Oct. 22, 1974 1 1 HIP FIXATIONDEVICE [76] Inventor: Richard F. Wagner, 62 San Jacinto Way, SanFrancisco, Calif. 94127 221 Filed: Nov. 12,1973

21 Appl. No.: 414,711

Primary ExaminerRichard A. Gaudet Assistant ExaminerJ. Yasko Attorney,Agent, or Firm-Townsend and Townsend [57] ABSTRACT A hip fixation devicefor reconstructing fractures of the upper end of the femurcomprising aspoon-shaped plate having a handle portion which extends laterally alongthe top of the femur shaft and a bowl portion which conforms to thelower portion of the greater trochanter. A plurality of bores transversethe bowl portion for receiving hip screws adapted to be driven into theupper end of the femur generally parallel to the long axis of the femurhead and a flat headed boss surrounds the outer opening of each boreagainst which the undersides of the screw heads seat. A cover plate isattached tightly over the outer side of the bowl portion against thescrew heads by means of bolts. It has a raised section on its inner sidewhich fits down between the screw heads to keep them from rotating. Apair of bending tools for bending the spoon shaped plate so that itconforms to the femur contour and a driving tool for driving the hipscrews into the femur are also disclosed.

9 Claims, 12 Drawing Figures P mgnnmzzmn v 35842.825 ai m n PAIENI001221974 sum as 4 HIP FIXATION DEVICE BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to a hip fixation deviceand tools which are used to conform and affix that device to a femur.

2. Description of the Prior Art A great variety of plates, nails, pins,screws and combinations thereof are presently used in performingreconstructions of fractures of the upper end of the femur. In generalthe presently used plates extend along the upper portion of the shaftand curve up and around a portion of the greater trochanter. They have aplurality of transverse bores through which bone screws are screwed intothe shaft and upper end of the femur. The screws which extend into theupper end of the femur are skewed relative to each other because of thecurvature of the plate about the greater trochanter. Such skewedfixation is less desirable than fixation along several lines parallel tothe long axis of the femur head. It is believed that the only deviceswhich permit fixation along such parallel lines are pins and nails whichare inserted independently of each other and have no associated plate.

All of the prior art fixation elements which are screwed or driven intothe upper end of the femur are susceptible to loosening or backing outwhichweakens or, in chronic instances, totally destroys the fixation.

SUMMARY OF THE INVENTION The present invention is a novel hip fixationdevice for use in reconstructing fractures of the upper end of the femurwhich permits fixation along a plurality of lines parallel to the longaxis of the femur head and inherently prevents the fixation elementsfrom loosening from or backing out of the upper end of the femur. Itcomprises a spoon-shaped plate having an elongated handle portion whichextends along the upper portion of the femur shaft and a bowl portionwhich is shaped to conform to the lower portion of the greatertrochanter. The bowl portion of the plate has a plurality of spacedbores, preferably four in a rectangular configuration, extendingtransversely through it for receiving the fixation elements. The outeropening of each bore has a boss surrounding it. The heads of the bossesare flat and parallel to each other so that when the heads of thefixation elements are driven into the femur flush to the heads of thebosses, the shanks of the elements will be parallel to each other. Thedevice also includes a cover plate which is placed over the outer sideof the bowl portion of the spoon-shaped plate and means for attaching ittightly thereover so as to exert positive compression on the heads ofthe fixation elements to prevent them from loosening from the femur. Theinside of the cover plate has a raised section which fits between theheads of the fixation elements to prevent them from turning and backingout of the femur.

Additional features of the invention are a pair of bending tools whichare used to bend the spoon-shaped plate so that it closely conforms tothe contour of the femur and a driving tool for driving the fixationelements into the upper end of the femur.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings FIGS. 1-6 illustratean embodiment of the device of this invention and FIGS. 7-12 illustratetools which are used to affix said device to a femur. Specifically:

FIG. 1 is a dimetric view of a hip fixation device according to thisinvention attached to a femur;

FIG. 2 is an enlarged sectional view taken along line 22 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is an exploded, enlarged view of the hip fixation device shown inFIG. 1;

FIG. 5 is a sectional view taken along line 55 of FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 3;

FIG. 7 is a dimetric view of a bending tool being used to bend the hipfixation device of FIG. 1;

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is a dimetric view of a tool used to attach the hip fixationdevice of FIG. 1 to a femur;

FIG. 10 is an enlarged sectional view taken along line 10l0 of FIG. 9;

FIG. 11 is a sectional view taken along line 11-11 of FIG. 10; and

FIG. 12 is an enlarged view of the head of the tool shown in FIG. 9 inposition to receive a screw for affixing the hip fixation device to afemur.

DETAILED DESCRIPTION OF EMBODIMENT SHOWN IN DRAWINGS As seen in FIG. 1the illustrated device is designed to accomplish an anatomicalreconstruction of a fracture of the upper end of a femur, generallydesignated 1, such as an intracapsular, intercervical orintertrochantoric fracture. It may also be employed in femoralarthrodeses and osteotomies.

The main component of the device is a spoon-shaped plate, generallydesignated 2, comprising an elongated handle portion 3 and a bowlportion 4. The handle portion 3 is convexly curved so that it generallyconforms to the curvature of the upper portion of shaft 5 of femur 1.The bowl portion 4 is similarly curved and angled from the handleportion so that it generally conforms to the curvature of the lowerportion of the greater trochanter 6 of femur l.

Bowl portion 4 has four equidistantly spaced, ovular bores 7 runningtransversely through it. Desirably bores 7 form either a 3/4 inch squareconfiguration or a 5/8 inch square configuration, which dimensions are,respectively, ideal for use with adult male and women or childrenpatients. The outer opening of each of bores 7 has aboss 8 surroundingit, the head 9 of which is flat. Bores 7 receive four hip screws 10having square heads 14 the flat undersides of which seat flush againstthe heads 9. As shown in FIGS. 1 through 3 hip screws 10 are adapted toextend through the upper end of femur 1 axially to the long axis of thehead 15 thereof (FIG. 1) in parallel relationship to each other withtheir square heads 14 aligned (FIG. 6) in a square configuration.

A curved, ovular cover plate 16 fits over the outer side of bowl portion4 and is seated against the top sides of heads 14 of hip screws 10. Theinner side of ovular cover plate 16 has a rectangular raised section 17(FIGS. 4 and 6) formed along its short axis which extends snugly betweenthe opposed sides of the aligned heads 14 of hip screws (FIGS. 2, 3 and6). When so positioned, section 17 prevents hip screws 10 from rotating.Cover plate 16 is secured to bowl portion 4 by two plow bolts 18 whichare threadedly received through two countersunk, threaded bores 19 whichtransverse bowl portion 4 at flared sections 20 thereof. Cover plate 16has two elongated holes 24 at opposite ends of its long axis throughwhich bolts 18 pass. Lock washers 25 and nuts 26 are threaded onto theshafts of bolts 18. By tightening nuts 26 positive compression isexerted on the heads 14 of screws 10 thereby keeping them in place andpreventing them from backing out of the femur.

The handle portion 3 of plate 2 has a plurality of countersunk bores 27transversing it through which bone screws 28 pass for purposes ofsecuring handle portion 3 to the shaft 5 of the femur.

The above described hip fixation device is used as follows. The surgeonfirst drills a guide bore into the upper end of the femur along apreselected line. (The hip is usually X-rayed at this point to make surethe line of the guide bore is proper.) A guide wire or pin is theninserted into the guide bore. Bowl section 4 of plate 2 has a centralhole 29 for receiving the guide wire and plate 2 is slipped over theguide wire up against the femur. In the event the angle between handleportion 3 and bowl section 4 is not such that permits a snug fit of theplate against the shaft 5 and greater trochanter 6, plate 2 must beremoved and bent. Bending tools, generally designated 30, 34 and shownin FIGS. 7 and 8, are used for this purpose.

As seen in FIGS. 7 and 8 tool 30 is adapted to grip the handle portion 3of plate 2, whereas tool 34 is adapted to grip bowl portion 4. Bendingtool 34 operates on a principal similar to that of a vise. It includesan upper jaw 35 and a lower jaw 36 pivotally interconnected at their oneends by a pair of bars 37 and pins 38, 39. Their other ends arereleasably interconnected by a swing bolt 40, one end of which isjournalled on a pin 41 within a way 42 in said other end of upper jaw35. Lower jaw 36 has a way (not shown) in its said other end forreceiving the other end of swing bolt 40. Said other end of swing boltis threaded and fitted with a wing nut and collar- (not shown) which areadapted to slide under the bottom side of lower jaw 35 when it and jaw36 are closed. The jaws 35, 36 are secured tightly together by merelytightening said wing nut.

The inner surface of lower jaw 36 has a dome shaped protrusion 46 (FIG.8) of the same curvature as the bowl portion 4. correspondingly theinner surface of upper jaw 36 has four spaced nipples 47 formed on itwhich register with bores 7 of bowl portion 4. As shown in FIG. 8 thebowl portion 4 is placed between jaws 35, 36 with the inner surfacethereof against dome shaped protrusion 46. When the jaws are closednipples 47 are slidably engaged within bores 7. In this manner said bowlportion is held firmly between the jaws.

Upper jaw 35 has an anvil plate 48 mounted on its side adjacent thelocation at which handle portion 3 emerges from between the jaws. Screws50 secure plate 48 to said side. The lower edge 51 of plate 50 has thesame curvature as handle portion 3 and is adapted to engage handleportion 3 at the point at which it joins bowl portion 4. A second anvilplate is mounted on lower jaw 36 at the side opposite anvil plate 48 forbending of plate 2 when it is positioned in tool 34 with handle portion3 extending in the direction opposite that shown in FIGS. 7 and 8. Theupper edge 56 of anvil plate 45 is convexly curved so as to engage theconcave surface of handle portion 3 at the point of its juncture withbowl portion 4.

Lower jaw 36 has a handle 52 attached to its bottom surface.

Bending tool 30 operates similarly to a positive, lock actioncompression wrench. It comprises a generally rectangular housing 53having a longitudinal channel 54 extending through its entire length.The surface defining the upper side of channel 54 has the same curvatureas handle portion 3. Otherwise channel 54 is rectangular. Disposedwithin channel 54 is a jaw member 55 adapted for vertical movementwithin channel 54. The top side of jaw member 55 also has the samecurvature as handle portion 3 and is spaced from said surface definingthe upper side of channel 54. Otherwise, it too is rectangular. A pairof screws 59 interconnect housing 53 and jaw member 55. As shown in FIG.8 screws 59 are received through bores 60 and counterbores 61 whichcombined extend from the bottom of housing 53 through to channel 54.Screws 59 have decreased diameter, threaded end portions 62 which arescrew threadedly received within bores 63 in the bottom of jaw member59. A compression spring 64 is seated within each counterbore 61, oneend of which bears on the shoulder of the counterbore and the other endof which bears on the bottom of the head of screw 59.

Tool 30 is equipped with a handle 65 having a threaded end 66 (FIG. 8).Threaded end 66 is screw threadedly received within a threaded bore 67located in the center of the bottom of housing 53 and opening throughsaid bottom to the channel 54. End 66 has a flat head 68 which isadapted to bear against the bottom of jaw member 55. Jaw member 55 israised and lowered within channel 54 by turning handle 65. By tighteninghandle 65 head 68 is moved upwardly against the bottom of jaw member 55.Further tightening forces member 55 upwardly within channel 54. Whenhandle 65 is backed off the weight of jaw member 55 and compressionsprings 64 force member 55 downwardly in channel 54.

Plate 2 is bent by locking bowl portion 4 within tool 34 and insertinghandle portion 3 longitudinally through the space in channel 54 betweenthe curved top of jaw member 55 and the curved surface defining theupper side of channel 54 and tightening handle 65. Such tighteningforces jaw member 55 up against handle portion 3 thereby locking itwithin channel 54. Handles 52 and 65 are then gripped and pulled inopposite directions thereby forcing the joint between handle portion 3and bowl portion 4 against the lower edge 51 of anvil plate 50 andbending said joint thereagainst.

After plate 2 is bent to conform to the femur it is replaced over theguide wire as described above. Using bores 7 and the guide wire asguides four parallel holes 66 (FIG. 9) are drilled with a bone drill inthe upper end of the femur. These holes are for the purpose of startinghip screws 10. Hip screws 14 may be screwed into the femur and drivenhome with a screw driver, generally designated 67 and shown partially inFIGS. 9 through 12. Screw driver 67 comprises a shaft 68 having an end69 which is flared at 70 and has a box socket 71 in it for receivinghead 14 of hip screw 10. The other end 72 of shaft 68 is adapted to fitinto a chuck 73 of a conventional drill or screw driver handle. At apoint along shaft 68 a series of four skived surfaces 74 are formed todefine a rectangular cross-section. The rectangle so defined is inalignment with the surfaces of box socket 71 so that the surfaces may beused to ascertain the position of heads 14 of hip screws for assuringcorrect seating of the heads with respect to cover plate 16. A temperedsteel spring retainer collar, generally designated 77, fits around end69. Collar 77 comprises a pair of clamping prongs 78 which are slidablysecured at one end about shaft 68 by means of a collar 79. Each prong 78has a bowed central section 80 which extends out around the flaring 70on end 69 and a semicircular nipper 81 at its other end.

FIG. 12 shows retainer collar 77 in a retracted position with the driverready to receive a screw 10. As shown the clamping prongs 78 areslightly spread apart due to their inherent spring tension. FIGS. 10 and11 show the retainer collar 77 in its operative position, holding ascrew 10 in place within socket 71 of driver 67. As shown the head 14 ofscrew 10 is secured within socket 71 and prongs 78 are clamped togethersnugly about end 69 with nippers 81 gripping the shaft of screw 10.Prongs 78 are held clamped together by a collar 78 which is slid aboutbowed section 80.

As shown in FIG. 9 after the screw 10 is inserted into the driver 67 andthe retainer collar is slid into its operative position with collar 82about bowed section 80 the screw 10 is inserted through a bore 7 inplate 2 into the corresponding start hole 66 and screwed into the femur.After the screw has been screwed in up to the nippers 81 the collar 82is slid off bowed section 80, causing the prongs 78 to spread and theretainer collar is slid back on shaft 68 exposing the remainder of thescrew 10. Screw 10 is then driven home with its head 14 aligned with theheads of the other screws 10 as described above. The cover plate 16 isthen put into position and tightened down as described above.

The fixation is finished by screwing bone screws 28 through holes 27into the shaft 5 of the femur.

Thus, the fixation device of this invention provides fixation along amultiplicity of parallel lines extending through the upper end of thefemur in which the primary fixation elements, i.-e. the hip screws, areheld within the upper end of the femur under positive compression and ina manner which prevents them from backing out of the femur and weakeningor even destroying the fixation.

Various modifications of the above described hip fixation device andtools may be made without departing from the spirit or scope of theinvention. Means other than said flat-headed bosses, such as a singlecontinuous fiat plate surface, might be used to ensure that the hipscrews remain parallel within the femur. Also, the undersides of thescrew heads might be appropriately contoured or the bores in the bowlportion might have contoured counterbores. Likewise, means other thanbolts and nuts might be used to attach the cover plate to thespoon-shaped plate. Further, the raised section which keeps the hipscrews from rotating could be independent of the cover plate andseparately attachable to the spoon-shaped plate. These modifications andother modifications which are obvious to one of ordinary skill in themechanical arts are intended to be within the scope of the followingclaims.

I claim:

1. A hip fixation device comprising:

a. a spoon-shaped plate comprising an elongated handle portion adaptedto extend laterally along and conform to the upper portion of the shaftof a femur and a bowl portion adapted to conform to the lower portion ofthe greater trochanter of said femur;

b. a plurality of spaced bores transversing the bowl portion said boresbeing adapted to receive hip screws therethrough in substantiallyparallel relationship to each other;

c. a flat plate surface surrounding the outer opening of each of thebores, against which the heads of the hip screws are adapted to seat;

d. a cover plate adapted to be attached over the outer side of the bowlportion and against the heads of said hip screws;

e. a raised portion on the inner side of the cover plate adapted to fitbetween the heads of said hip screws and prevent'rotation thereof; and

f. means for attaching the cover plate over the outer side of the bowlportion whereby pressure is exerted against the heads of the screws tokeep them from loosening from the femur.

2. The hip fixation device according to claim 1 in which the handleportion has a plurality of bores transversing it for receiving bonescrews therethrough.

3. The hip fixation device of claim 1 including:

g. a boss surrounding the outer opening of each of the bores, againstwhich the heads of the hip screws are adapted to seat.

4. The hip fixation device according to claim 1 in which there are fourof said bores in a square configuration sized to the dimensions of theneck of said femur.

5. The hip fixation device according to claim 1 wherein said raisedportion is a vertical, generally rectangular bar.

6. The hip fixation device according to claim 1 wherein said means forattaching the cover plate over the outer side of the bowl portionincludes:

g. a pair of bolts adapted to be received through said bowl portion andcover plate; and

h. a pair of nuts adapted to be screw threadedly received on the shanksof said bolts.

7. The hip fixation device according to claim 3 in which said bores areovular and the tops of the bosses are planar whereby the substantiallyparallel relationship of the hip screws is permitted and maintained.

8. A hip fixation device comprising:

a. a spoon-shaped plate comprising an elongated handle portion adaptedto extend laterally along and conform to the upper portion of the shaftof a femur and a bowl portion adapted to conform to the lower portion ofthe greater trochanter of the femur;

four ovular bores transversing said bowl portion said bores being in asquare configuration sized to the dimensions of the neck of said femurand being adapted to receive hip screws therethrough in substantiallyparallel relationship to each other; c. a boss surrounding the outeropening of each of said bores, the tops of said bosses being fiat andplanar and against which the heads of the hip screws are adapted to seatwhereby said substantially parallel relationship is maintained;

d. a cover plate adapted to be attached over the outer side of the bowlportion and against the heads of said hip screws;

e. a vertical bar on the inner side of said cover plate adapted to fitbetween the heads of the hip screws and prevent rotation thereof; f. aplurality of bolts adapted to be received through said bowl portion andcover plate; and i g. a plurality of nuts adapted to be screw threadedlyversing it for receiving bone screws therethrough.

1. A hip fixation device comprising: a. a spoon-shaped plate comprising an elongated handle portion adapted to extend laterally along and conform to the upper portion of the shaft of a femur and a bowl portion adapted to conform to the lower portion of the greater trochanter of said femur; b. a plurality of spaced bores transversing the bowl portion said bores being adapted to receive hip screws therethrough in substantially parallel relationship to each other; c. a flat plate surface surrounding the outer opening of each of the bores, against which the heads of the hip screws are adapted to seat; d. a cover plate adapted to be attached over the outer side of the bowl portion and against the heads of said hip screws; e. a raised portion on the inner side of the cover plate adapted to fit between the heads of said hip screws and prevent rotation thereof; and f. means for attaching the cover plate over the outer side of the bowl portion whereby pressure is exerted against the heads of the screws to keep them from loosening from the femur.
 2. The hip fixation device according to claim 1 in which the handle portion has a plurality of bores transversing it for receiving bone screws therethrough.
 3. The hip fixation device of claim 1 including: g. a boss surrounding the outer opening of each of the bores, against which the heads of the hip screws are adapted to seat.
 4. The hip fixation device according to claim 1 in which there are four of said bores in a square configuration sized to the dimensions of the neck of said femur.
 5. The hip fixation device according to claim 1 wherein said raised portion is a vertical, generally rectangular bar.
 6. The hip fixation device according to claim 1 wherein said means for attaching thE cover plate over the outer side of the bowl portion includes: g. a pair of bolts adapted to be received through said bowl portion and cover plate; and h. a pair of nuts adapted to be screw threadedly received on the shanks of said bolts.
 7. The hip fixation device according to claim 3 in which said bores are ovular and the tops of the bosses are planar whereby the substantially parallel relationship of the hip screws is permitted and maintained.
 8. A hip fixation device comprising: a. a spoon-shaped plate comprising an elongated handle portion adapted to extend laterally along and conform to the upper portion of the shaft of a femur and a bowl portion adapted to conform to the lower portion of the greater trochanter of the femur; b. four ovular bores transversing said bowl portion said bores being in a square configuration sized to the dimensions of the neck of said femur and being adapted to receive hip screws therethrough in substantially parallel relationship to each other; c. a boss surrounding the outer opening of each of said bores, the tops of said bosses being flat and planar and against which the heads of the hip screws are adapted to seat whereby said substantially parallel relationship is maintained; d. a cover plate adapted to be attached over the outer side of the bowl portion and against the heads of said hip screws; e. a vertical bar on the inner side of said cover plate adapted to fit between the heads of the hip screws and prevent rotation thereof; f. a plurality of bolts adapted to be received through said bowl portion and cover plate; and g. a plurality of nuts adapted to be screw threadedly received on the shanks of said bolts whereby said cover plate is secured to said bowl portion and pressure is exerted against the heads of said hip screws to keep them from loosening from the femur.
 9. The hip fixation device according to claim 8 in which the handle portion has a plurality of bores transversing it for receiving bone screws therethrough. 